JP3612231B2 - Nozzle device and developing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing method in which a photosensitive film laminated on the surface of a substrate to be processed is developed after exposure.
[0002]
The present invention also relates to a nozzle device for spraying a processing liquid onto the surface of a substrate to be rotated.
[0003]
[Prior art]
In general, as schematically shown in FIG. 13, a semiconductor chip is formed by forming a circuit on a semiconductor wafer (hereinafter referred to as a wafer) as a substrate to be processed and forming an aluminum electrode 11 thereon. A protective film 12 made of polyimide is laminated on the chip 1. The semiconductor chip 1 is supported by a lead frame (not shown), and is molded in a state where the aluminum electrode 11 and the lead are connected by a bonding wire 13.
[0004]
By protecting the circuit formed on the chip 1 with this protective film 12, it is possible to prevent the circuit from being affected when the wafer is cleaved to obtain the chip 1, and the circuit is excessively formed during molding or the like. It prevents the external force from reaching.
[0005]
The protective film 12 is obtained by, for example, applying a photosensitive negative or positive polyimide on the wafer, heating it, performing polyimide exposure and polyimide development to expose the surface of the aluminum electrode 11, and further curing the polyimide. It is done. For development, for example, an apparatus used for forming a resist pattern in a semiconductor device manufacturing process can be used. As such a developing apparatus, for example, an apparatus as shown in FIG. 14 is known. In the figure, 21 is a processing chamber, 22 is a holding table for a wafer W, 23 is a rotating mechanism for rotating the holding table 22, and 24. Is a developing solution supply nozzle, and 25 is a rinsing solution supply nozzle.
[0006]
[Problems to be solved by the invention]
However, since polyimide is difficult to dissolve at the time of development, a large amount of developer is required to sufficiently remove unnecessary portions, but if the developer flow rate to the nozzle is increased in order to finish the development process in as short a time as possible, Since it becomes difficult to form a uniform developer film on the surface of the polyimide film, the flow rate of the developer cannot be increased unnecessarily.
[0007]
In addition, since the diameter of wafers has been increasing more and more recently, a larger amount of developer is required, and in the conventional apparatus having only one developer supply nozzle as shown in FIG. 14, the flow rate of the developer is uniform. If it is set within a range where a simple developer film can be formed, the development time becomes longer and the throughput is lowered.
[0008]
Also, after supplying the developer to the surface of the polyimide film and removing unnecessary parts, if the rinse solution is supplied after the supply of the developer is stopped to shrink the remaining pattern portion swollen by the developer, a large stress is applied to the pattern. There is a risk of cracks.
[0009]
The present invention has been made under such circumstances, and an object of the present invention is to reduce the stress acting on the pattern when the development processing is completed in a shorter time and the pattern is changed from the developing solution to the rinsing solution as much as possible. An object of the present invention is to provide a developing method capable of achieving the above.
[0010]
Another object of the present invention is to provide a nozzle device capable of supplying a large amount of two different types of processing liquids in a short time in an apparatus for spraying a processing liquid onto the surface of a rotating substrate to be processed. That is.
[0011]
[Means for Solving the Problems]
The nozzle device according to the present invention is a device that sprays two different types of processing liquids on the surface of a rotating substrate to be processed, and a pair of first processing liquid nozzles and second nozzles that can be arranged in a straight line along the substrate to be processed. A treatment liquid nozzle is provided, the pair of first treatment liquid nozzles are oriented in the same direction, and the pair of second treatment liquid nozzles are oriented in the same direction and opposite to the first treatment liquid nozzle. It is characterized by that.
The nozzle device according to the present invention includes a means for horizontally holding a substrate to be processed and rotating the substrate, a pair of first processing liquid nozzles for spraying the first processing liquid on the rotating substrate to be processed, and a substrate to be processed. A pair of second processing liquid nozzles for spraying the second processing liquid in a wider area including the first processing liquid supply area on the substrate, the pair of first processing liquid nozzles and the pair of second processing. The liquid nozzles are arranged in a straight line at positions facing the substrate to be processed, the pair of first processing liquid nozzles are both arranged in the same direction and with the same inclination, and the pair of second processing liquid nozzles are both the same. It is characterized by being arranged in the same direction and with the same inclination and facing in the opposite direction to the first treatment liquid nozzle.
[0012]
According to the present invention, the processing liquid can be supplied in a large amount and uniformly over a wide range in a short time to the surface of the substrate to be rotated.
[0013]
In the present invention, the two first processing liquid supply regions by the pair of first processing liquid nozzles partially overlap each other, and the two second processing liquid supply by the pair of second processing liquid nozzles It is desirable that the regions also overlap with each other. For example, the first processing solution is a developer, and the second processing solution is a rinsing solution. Further, the supply of the developer is performed by spraying the developer atomized by the gas, and the supply of the rinse liquid is also preferably performed by spraying the rinse liquid atomized by the gas. Further, the first processing liquid nozzle and the second processing liquid nozzle supply the developing solution to the substrate to be processed by the first processing liquid nozzle, and then supply the developing solution to the substrate to be processed by the first processing liquid nozzle. It is desirable that the rinsing liquid is supplied to the substrate to be processed by the second processing liquid nozzle, and then the rinsing liquid is supplied to the substrate to be processed by the second processing liquid nozzle.
[0014]
The developing method according to the present invention includes a step of spraying a developer from the pair of first processing liquid nozzles on the substrate to be processed using the nozzle device, and the pair of second on the substrate to be processed. A step of spraying the rinsing liquid from the processing liquid nozzle, and a step of simultaneously spraying the developing liquid and the rinsing liquid by the first processing liquid nozzle and the second processing liquid nozzle during the transition from the developing process to the rinsing process; , Including. In the present invention, when spraying the developer or the rinsing liquid, first, only the gas is first supplied from the pair of first processing liquid nozzles toward the substrate to be processed, and then the gas and the developing liquid are supplied. The post-developer supply is stopped and only the gas is supplied. In the rinsing step, only the gas is first supplied from the second processing liquid nozzle to the substrate to be processed, and then the gas and the rinsing liquid are supplied. Thereafter, the substrate of the rinsing liquid is stopped and only the gas is supplied.
[0015]
According to the present invention, a large amount of a developing solution or a rinsing solution can be supplied to the surface of the rotating substrate to be processed over a wider range in a short time, and the chemical reaction by the developing solution is gradually stopped to develop the developing substrate. Since the pattern swollen by the liquid is gradually contracted, it is possible to prevent an excessive stress from being applied to the pattern.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 are diagrams showing an example in which the nozzle device according to the present invention is used in carrying out the developing method according to the present invention. A spin chuck 31 rotatably supported by a motor and lifting means (not shown) and a pair of nozzles 41 and 42 and nozzles 43 and 44 that can be disposed above the wafer W vacuum-sucked by the spin chuck 31. , A rail 5 that guides the nozzle device 4 to move parallel to the wafer W, an outer cup 32 that surrounds the periphery of the wafer W and receives a processing liquid such as a developer or a rinsing liquid, and And an inner cup 33 that can freely move up and down. A drain 34 is connected to the outer cup 32.
[0017]
The nozzle device 4 is a spray that sprays, for example, a developer, which is a first processing liquid, onto the surface of the wafer W on a support beam 45 that extends perpendicularly to the rail 5 and is movable along the rail 5 by a drive mechanism (not shown). Type developer supply nozzles 41, 42 and spray type rinse solution supply nozzles 43, 44 for spraying, for example, a rinse solution, which is a second processing solution, on the surface of the wafer W are alternately arranged along the support beam 45. The arrangement is fixed.
[0018]
For example, in the example illustrated in FIG. 1, the developer supply nozzle 41, the rinse liquid supply nozzle 43, the developer supply nozzle 42, and the rinse liquid supply nozzle 44 are sequentially arranged from the left side.
[0019]
The pair of developing solution supply nozzles 41 and 42 are inclined downward in the right direction in FIG. 1, and the developing solution supply nozzle 41 disposed on the leftmost side is positioned slightly to the right of the center from the left end of the wafer W. The range surrounded by the two-dot chain line is the developer supply region 61, and the other developer supply nozzle 42 supplies the developer solution to the range surrounded by the two-dot chain line from the position slightly to the left of the center of the wafer W to the right end. Region 62 is designated. Accordingly, the two developer supply regions 61 and 62 partially overlap each other on the surface of the wafer W.
[0020]
The pair of rinsing liquid supply nozzles 43 and 44 are inclined downward to the left in FIG. 1, and the rinsing liquid supply nozzle 44 disposed on the rightmost side is slightly to the left of the center from the right end of the wafer W. The range surrounded by the two-dot chain line up to the position is the rinse liquid supply region 64, and the other rinse liquid supply nozzle 43 is the rinse liquid in the range surrounded by the two-dot chain line from the position slightly to the right of the center of the wafer W to the left end. The supply area 63 is used. Accordingly, the two rinse liquid supply regions 63 and 64 partially overlap each other on the surface of the wafer W.
[0021]
The range formed by the two rinse liquid supply regions 63 and 64 is the same as or wider than the range formed by the two developer supply regions 61 and 62 (see FIG. 8). Here, the developer supply nozzles 41 and 42 are inclined in the same direction, while the rinse liquid supply nozzles 43 and 44 are inclined in the same direction and in the opposite direction to the direction of the developer supply nozzles 41 and 42. If the developer supply nozzles 41 and 42 and the rinse solution supply nozzles 43 and 44 are inclined in the same direction, a liquid ball is formed when the developer and the rinse solution are sprayed for a lifetime. This is because the rinse liquid cannot be uniformly sprayed on the wafer W.
[0022]
FIG. 2 shows the case where the nozzle device 4 is in the standby position. When spraying the developer or the rinse solution, the nozzle device 4 moves to the left in FIG. 2 and has a diameter passing through the center of the wafer W. Located above, spraying takes place. In FIG. 1 and FIG. 2, reference numeral 46 denotes a processing liquid (developing liquid or rinsing liquid) introduction section, which is connected to a processing liquid supply tank (not shown) via a pipe (not shown). Reference numeral 47 denotes a nitrogen gas introduction part, which is connected to a nitrogen gas cylinder (not shown) through a pipe (not shown). FIG. 3 is a cross-sectional view showing the structure of the main part of the developer supply nozzle 41. The other developing solution supply nozzle 42 and the rinsing solution supply nozzles 43 and 44 have the same structure, and thus description thereof is omitted.
[0023]
The nozzle 41 (42, 43, 44) accelerates the flow rate of the processing liquid flowing into the nozzle base 71 having a receiving hole 75 for receiving the processing liquid sent through the processing liquid introducing section 46 (not shown). The ejection part 72 having a narrow ejection hole 76 for ejecting the nozzle and the nozzle tip part 73 having the pore 77 for spraying the treatment liquid ejected therefrom in a spray form with nitrogen gas, and the nozzle tip part 73 are fixed. The fixed cylinder part 74 for doing this is comprised.
[0024]
The nozzle base 71 has an attachment hole 78 for attaching the nitrogen gas introduction part 47 (not shown), and an attachment convex part 79 fitted into the gas flow path of the nitrogen gas introduction part 47. The mounting projection 79 is connected in communication with a gas inlet 80 provided in the nozzle base 71, and is also connected in communication with a gas flow path in a nitrogen gas inlet 47 (not shown).
[0025]
The emission part 72 is accommodated in a space defined by the nozzle base 71 and a fixed cylinder part 74 screwed to the lower end part thereof, and between the upper end edge of the emission part 72 and the nozzle base 71. An O-ring 81 for maintaining airtightness is interposed. A nitrogen gas circulation hole 82 is provided around the ejection hole 76 of the emission part 72, and the upper end edge of the nozzle tip 73 is in contact with the circumference of the circulation hole 82 from below. And the emission part 72 is being fixed by the nozzle tip part 73 being pressed down by the fixed cylinder part 74.
[0026]
The upper end of the fixed cylinder part 74 is separated from the lower surface of the attachment part of the nozzle base part 71 to the fixed cylinder part 74, thereby forming an annular space 83. The annular space 83 communicates with the gas introduction port 80 and the gas space 84 defined by the emission portion 72 and the fixed cylinder portion 74, and further communicates with the gas flow hole 82 of the emission portion 72.
[0027]
The treatment liquid ejected from the ejection hole 76 of the emission part 72 into the space 85 defined by the nozzle tip part 73 and the emission part 72 is atomized by the nitrogen gas blown out from the gas flow hole 82, and the nozzle tip part The light is emitted from 73 pores 77.
[0028]
Next, a procedure for developing the polyimide film coated on the surface of the wafer W and exposed using the nozzle device 4 having the above-described configuration will be described with reference to FIGS.
[0029]
First, the spin chuck 31 is raised above the cups 32 and 33, and the wafer W that has already been coated with polyimide and exposed in the previous process is transferred from the arm (not shown) to the spin chuck 31. When the spin chuck 31 is lowered, the nozzle device 4 is moved onto the center of the wafer W while rotating the wafer W. Then, only nitrogen gas is supplied to the developer supply nozzles 41 and 42, and only nitrogen gas is blown out from these nozzles 41 and 42. At that time, nothing comes out from the rinsing liquid supply nozzles 43 and 44 (see FIG. 4).
[0030]
Next, the developer is supplied together with nitrogen gas to the developer supply nozzles 41 and 42, and the developer is sprayed from the nozzles 41 and 42 in a spray form (see FIG. 5). The developer is composed of, for example, normal methyl 2-pyrrolidinone (NMP) and cyclohexane.
[0031]
When a predetermined time elapses in this state, only the nitrogen gas is supplied to the rinsing liquid supply nozzles 43 and 44 and only the nitrogen gas is blown out from the nozzles 43 and 44. At that time, the developer is still sprayed from the developer supply nozzles 41 and 42 (see FIG. 6).
[0032]
When a predetermined developing time has elapsed, the rinsing liquid is supplied to the rinsing liquid supply nozzles 43 and 44 together with the nitrogen gas, and the rinsing liquid is sprayed from these nozzles 43 and 44 (see FIG. 7). Therefore, at this time, as shown in FIG. 8, since both the developer and the rinsing liquid are sprayed on the surface of the wafer W, the chemical reaction between the polyimide film and the developer is gradually stopped, and the generation of stress is alleviated. Is done. The rinse liquid is made of, for example, butyl acetate and propylene glycol monomethyl ether alcohol (PGMEA).
[0033]
In the example of FIG. 8, the rinsing liquid supply regions 63 and 64 are sprayed in a wider range than the developer supply regions 61 and 62, but the spray ranges of both may be the same.
[0034]
Subsequently, the supply of the developer to the developer supply nozzles 41 and 42 is stopped, only the nitrogen gas is supplied, and only the nitrogen gas is blown out from these nozzles 41 and 42 (see FIG. 9). This is to prevent the developer from dripping onto the wafer W after the supply is stopped. Further, since the supply of the developing solution is stopped, only the rinsing solution is sprayed on the entire surface of the wafer W. Therefore, the reaction between the developing solution and the polyimide film is completely stopped, and the pattern swollen by the developing solution contracts. In addition, a back rinse process is performed as needed.
[0035]
Subsequently, the supply of the rinsing liquid to the rinsing liquid supply nozzles 43 and 44 is stopped, only the nitrogen gas is supplied, and only the nitrogen gas is blown out from these nozzles 43 and 44 (see FIG. 10). This is to prevent the rinse liquid from dripping onto the wafer W after the supply is stopped. In FIG. 10, the nitrogen gas from the developer supply nozzles 41 and 42 is stopped, but may be discharged.
[0036]
Then, after the wafer W is continuously rotated and spin-dried, the nozzle device 4 is returned to the original standby position, the rotation of the wafer W is stopped, and the process is ended.
[0037]
According to the above-described embodiment, two nozzles 41, 42, 43, and 44 for atomizing the developer and the rinsing liquid and spraying them in a spray form are provided, so that a large amount of development is performed on the surface of the wafer W. Since the liquid or the rinsing liquid can be supplied uniformly over a wider range in a short time, it is possible to prevent a decrease in throughput when forming a protective film pattern made of polyimide.
[0038]
Further, according to the above-described embodiment, by spraying the developer and the rinsing liquid at the same time, the process of spraying the developer and the rinsing liquid at the same time when moving from the development process to the rinsing process is interposed, and the process In FIG. 11A, for example, the rinsing liquid supply area is made wider than the developer supply area (or may be the same area) so that only the developer is not supplied to the pattern. Then, the chemical reaction between the developer and the polyimide gradually stops, and the shrinkage of the swollen pattern P1 gradually occurs as shown in FIG. Therefore, it is possible to prevent an excessive stress from being applied to the contracted pattern P2, and to prevent generation of cracks. In other words, if spraying of the rinsing liquid is started at the same time as the spraying of the developer is stopped, the contraction of the swollen pattern occurs abruptly, and excessive stress acts on the pattern to easily generate cracks. Can prevent it.
[0039]
Further, according to the above-described embodiment, since the plurality of nozzles 41, 42, 43, 44 are aligned in a straight line, the space for storing the nozzle device 4 during standby is small, and a storage space is provided beside the cup 32. Can be secured. For example, four nozzles may be arranged in a cross shape. In this case, the storage space of the nozzle device during standby becomes larger than when the nozzles are arranged in a straight line. It is preferable to arrange the nozzles in a straight line.
[0040]
Next, an outline of an example of a coating / developing apparatus incorporating the nozzle device according to the present invention will be described with reference to FIG.
[0041]
In FIG. 12, 9 is a cassette loading / unloading stage for loading / unloading wafer cassettes. For example, 25 cassettes C are loaded by, for example, an automatic transfer robot. On the far side of the carry-in / out stage 9, for example, when viewed from the carry-in / out stage 9, for example, a coating / developing system unit is disposed on the left side, and a heating / cooling system unit is disposed on the right side.
[0042]
In the coating / developing unit, for example, two developing units 91 are provided in the upper stage, and two coating units 92 are provided in the lower stage. In the heating / cooling system unit, a heating unit 93, a cooling unit, a hydrophobizing unit, a delivery unit, and the like are arranged above and below.
[0043]
Further, a wafer transfer arm not shown in the figure is provided between the coating / developing unit and the heating / cooling unit. The wafer transfer arm is configured to be movable up and down, to the left and right, to the front and back, and to be rotatable about a vertical axis, for example, a coating / developing system unit, a heating / cooling system unit, a loading / unloading stage 9 and an interface unit 94 to be described later. The wafer W is transferred between them.
[0044]
When the interface unit 94 includes the coating / developing system unit and the heating / cooling system unit described above as a clean track, the interface unit 94 is interposed between the clean track and the exposure device 95, and both are connected by a transport system (not shown). Wafers are transferred between devices.
[0045]
The flow of wafers in this apparatus will be described. First, a wafer cassette C storing wafers from outside is loaded into the loading / unloading stage 9, and the wafer is taken out from the cassette C by a transfer arm not visible in FIG. Is passed on. Next, the wafer transfer arm transfers the wafer W on the delivery unit to the hydrophobic treatment unit, and the wafer W is subjected to the hydrophobic treatment here, and then the polyimide liquid is applied by the coating unit 92 so that the polyimide film is formed. It is formed. The wafer coated with the polyimide film is heated by the heating unit 93 and then sent to the exposure device 95 through the interface unit 94, where exposure is performed through a mask corresponding to the pattern.
[0046]
Thereafter, the wafer W is heated by the heating unit 93, then cooled by the cooling unit, and subsequently sent to the developing unit 91 for development processing to form a protective film. Thereafter, the wafer W is transferred to the heating unit 93 by the wafer transfer arm, cured there, and returned to the cassette C on the loading / unloading stage 9.
[0047]
In the above, the present invention is not limited to a developing solution and a rinsing solution, and the processing solution may be provided with three or more nozzles for spraying two kinds of processing solutions, or applied to a normal resist film developing process. May be.
[0048]
【The invention's effect】
As described above, according to the present invention, a large amount of a developing solution or a rinsing solution can be uniformly supplied to a surface of a rotating substrate to be processed over a wider range in a short time, thereby preventing a decrease in throughput. Can do. Further, the chemical reaction by the developing solution is gradually stopped, and the pattern swollen by the developing solution is gradually contracted. Therefore, it is possible to prevent an excessive stress from being applied to the pattern, thus preventing the occurrence of cracks.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing an example of a developing device to which a nozzle device according to the present invention is applied. FIG. 2 is a plan view showing a main part of the developing device.
FIG. 3 is a cross-sectional view showing a main part of a nozzle of the developing device.
FIG. 4 is a schematic diagram showing one step of a process for performing development processing using the nozzle device.
FIG. 5 is a schematic view showing one step in a process of performing development processing using the nozzle device.
FIG. 6 is a schematic diagram showing one step of a process for performing development processing using the nozzle device.
FIG. 7 is a schematic diagram showing one step of a process for performing development processing using the nozzle device.
FIG. 8 is a schematic view showing a spray region by the nozzle device.
FIG. 9 is a schematic diagram showing one step of a process for performing development processing using the nozzle device.
FIG. 10 is a schematic diagram showing one step in a process of performing development processing using the nozzle device.
FIG. 11 is a schematic diagram showing a state in which a pattern contracts by spraying a rinsing liquid.
FIG. 12 is a schematic perspective view showing a coating / developing apparatus to which the nozzle device is applied.
FIG. 13 is a schematic diagram showing a structure of a semiconductor chip.
FIG. 14 is a schematic diagram illustrating a configuration of a conventional developing device.
[Explanation of symbols]
W wafer (substrate to be processed)
41, 42 Developer supply nozzle (first processing solution nozzle)
43, 44 Rinsing liquid supply nozzle (second processing liquid nozzle)
61, 62 Developer supply region 63, 64 Rinse solution supply region

Claims (7)

In an apparatus for spraying two different types of processing liquids on the surface of a substrate to be rotated,
Comprising a pair of first treatment liquid nozzles and a pair of second treatment liquid nozzles that can be arranged in a straight line along the substrate to be treated;
The pair of first processing liquid nozzles are oriented in the same direction, and the pair of second processing liquid nozzles are oriented in the same direction and opposite to the first processing liquid nozzle. . Means for holding the substrate to be processed horizontally and rotating the substrate;
A pair of first processing liquid nozzles for spraying the first processing liquid on the substrate to be rotated;
A pair of second processing liquid nozzles for spraying the second processing liquid on a wider area including the first processing liquid supply area on the substrate to be processed;
The pair of first processing liquid nozzles and the pair of second processing liquid nozzles are arranged in a straight line at positions facing the substrate to be processed,
The pair of first processing liquid nozzles are both arranged in the same direction and with the same inclination, and the pair of second processing liquid nozzles are both in the same direction and with the same inclination, and further face the opposite direction to the first processing liquid nozzle. A nozzle device characterized by being arranged. The two first processing liquid supply regions by the pair of first processing liquid nozzles have a part thereof overlapping each other,
3. The nozzle device according to claim 1, wherein two second processing liquid supply regions by the pair of second processing liquid nozzles also partially overlap each other. 4. The nozzle device according to claim 1, wherein the first processing liquid is a developer and the second processing liquid is a rinsing liquid. 5. The developer is supplied by spraying a developer atomized by a gas, and the rinse liquid is also supplied by spraying a rinse liquid atomized by a gas. Item 4. The nozzle device according to Item 4. Using the device of claim 1 or claim 2,
Spraying the developer from the pair of first processing liquid nozzles on the substrate to be processed;
Spraying a rinse liquid from the pair of second processing liquid nozzles on the substrate to be processed;
And a step of spraying the developer and the rinsing liquid simultaneously with the first processing liquid nozzle and the second processing liquid nozzle during the transition from the developing process to the rinsing process. In the development process, only the gas is first supplied from the pair of first processing liquid nozzles toward the substrate to be processed, then the gas and the developing liquid are supplied, and then the supply of the developing liquid is stopped and only the gas is supplied. In the rinsing step, only the gas is first supplied from the second processing liquid nozzle toward the substrate to be processed, then the gas and the rinsing liquid are supplied, and then the rinsing liquid substrate is stopped and only the gas is supplied. The developing method according to claim 6, wherein the developing method comprises:

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